Pin tumbler locks in the form of cylinder locks have been used in vehicles for generations to limit access to and operation of the vehicles to authorized individuals in possession of a key matching those cylinder locks. Generally these cylinder locks include an outer casing or cylinder, a plug held in that cylinder, a keyway in the plug to receive a key blade and a set of spring-loaded key pins and corresponding driver pins.
The key blade is cut to a particular pattern or shape and is inserted into the keyway in order to operate the lock. When an improper key is inserted into the keyway, the key pins straddle the shear point where the plug meets the cylinder housing preventing the lock from opening or the ignition switch from turning to start the vehicle. In contrast, when the proper key is inserted into the keyway, the pins rise causing the meeting points of the key pins and cooperating driver pins to all align along the shear point where the plug meets the cylinder housing. This allows the plug to rotate thereby opening the door lock or turning the ignition switch of the vehicle.
For many years now vehicles have also incorporated an electronic security, immobilizer or magnetic coupled transponder system on the ignition switch. More specifically, the ignition switch includes an induction coil and the key is provided with a cooperating winding connected to a transponder. When the key is inserted into the keyway of the ignition switch, the induction coil is activated and sends out an electromagnetic field of energy. The windings associated with the transponder absorb that energy and power the electronic transponder to emit a signal. Typically the signal is an alphanumeric sequence that is considered an identification or key code. The induction coil reads the signal and sends it to the ignition control module. If the signal is recognized as an accepted identification code for authorized operation of the vehicle, other electronic components in the vehicle are set in the motion to allow the vehicle to start and the engine to continue running.
Essentially the new electronic immobilizer systems based on transponders are superior to key lock cylinders. They provide more than a billion unique combinations versus thousands of unique combinations for key lock cylinders. The electronic immobilizer systems have effectively rendered ignition key lock cylinders redundant secondary systems that are unnecessary. Thus, key lock systems are a legacy of an earlier age of vehicle design that now effectively add unnecessary cost to vehicle production.
This document relates to a vehicle security system devoid of any ignition lock cylinder, any door lock cylinder and keys including cut key blades for operation of such cylinders.